The long range goals of my work are to detemine the mechanisms of cellular motility in normal and transformed cells. I propose to directly test whether or not the contractile proteins have a role in force production for cellular motility. My approach will be to produce specific antibody inhibitors of contractile protein function, to microinject them into living cells, and to analyze their effects on cell movements, chromosome movement in mitosis, and cytokinesis. In this way I can test whether or not contractile protein function is among the phenotypic changes that distinguish normal from transformed cells. These experiments provide a direct test for the relevance of the morphological changes in the distribution of the contractile proteins observed upon transformation. This project requires expertise in five major disciplines: the biochemistry of contractile proteins, the practical immunology and cell culture experience required for production of monoclonal and monospecific antibodies, the technique of single cell microinjection, and the mass manipulation of virus for cell transformation. This approach, the development of customized inhibitors of contractile protein function in vitro and their subsequent injection into living cells is currently the most direct and possibly the only way to relate our current understanding of the biochemical properties of the nonmuscle contractile proteins to the numerous and complex interactions that give rise to motility in living cells. Understanding of cell motility is essential to complete analysis of the transformed state and may provide new insights for alternate approaches to cancer therapy in vivo.